FIG. 1 shows the circuit of a DC to AC inverter suitable for converting a source of DC power to a standard mains electrical AC voltage and frequency. The inverter is of a general type well known in the art where a DC to DC converter utilising a high frequency transformer steps up the voltage of the source of DC power to a higher DC voltage, which in turn is converted to a mains voltage AC output by means of pulse width modulation (PWM) followed by low pass filtering.
In the field of DC to AC inverters it is common for the DC power source to be a 12V, 24V, or 48V battery and for the inverter output to be a 230V 50 Hz or 115V 60 Hz AC voltage. Almost all these inverters use some form of switching circuit in conjunction with a transformer to step up the relatively low DC input voltage to the level required to produce the AC output. The switching circuit produces rapidly changing currents that cannot be supplied from the battery because of the inductance of the battery connection leads. To supply these currents, a capacitor bank is normally connected across the DC supply connections inside the inverter enclosure. Aluminium electrolytic capacitors are almost always used for the capacitor bank. In the sizes required for all but the smallest inverters these capacitors are available with either leads designed to be placed through holes in a printed circuit board (PCB) and soldered to the PCB conductors, or with screw terminals that allow the capacitor to be connected to the PCB conductors by screws passing through holes in the PCB. Sometimes laminated busbars are used to connect the capacitors in the capacitor bank together. These are produced by a different process to that used for PCBs, but functionally they are the same as both can be used to produce conducting layers separated by an insulator and both have similar interconnectivity resistance and inductance properties.
Power losses can occur in various portions of the inverter, including due to the use and interconnection of multiple PCBs and/or laminated busbars. It is desirable to minimise losses as much as possible in order to improve the efficiency of the inverter.